There are various resources and sites you can visit to get great ideas for building your vans off grid power. Below are sites I used:
- Facebook groups
- Google images
When the question about solar comes up in most FB groups there aren’t enough people knowledgeable of the process to help, or those who know how usually explains how in language difficult to understand. So I wrote this article to make it simple.
The story begins with batteries
Say you have two 35Ah (amp hour) batteries.
2 x 35 = 70
That’s 70 total amp hours.
Your batteries are 12 volt batteries. Multiply the amp hours by 12.
12 x 70 = 840
You have a total of 840 watts of available power to power all of your devices.
Then there’s using the batteries
You want charge your iPad. A iPad Air 2014 uses about 45 watts.
To calculate how long you can keep the iPad plugged into your battery, divide 45 from the 840 available watts.
840 / 45 = estimates 19 hours
You can left your iPad plugged into your 12 volt system you will drain your battery.
But that’s a very simple explanation because usually your running more than one device, like a refrigerator, TV, game console, and etc.
Wait there’s more to know
The idea behind off grid power is to plug in and use more than one device. Let’s look at how you calculate that.
- iPad = 44 watts
- 12 volt TV 62 watts
- iPhone 12 watts
44 + 62 + 12 = 118 watts
Now divide 118 (watts used) by the 840 (battery) watts.
840 / 122 = estimates 6 hours
You can run all these devices together for 6 hour before the battery is dead.
Recharging your batteries
Your batteries need a charging source. I will list 4 of them.
You can use the following methods to recharge your system batteries.
- Van alternator
- Shore power with a battery charger
- Solar panels
- Gas generator
Inverters are bad
By default your van runs off 12 volt DC (Direct Current).
Household appliances run on 110 volt AC (Alternating Current).
In order to use 110 volt appliances in your van you need a inverter.
If you plan to use sensitive devices in your van, like computers, gaming consoles, things that could damaged easily if a surge happens or a loss of power. You need a sine wave inverter. It’s more expensive but it offers protection for your devices should there not be enough power.
Why I don’t like inverters
A inverter needs to convert 12 DC to 110 AC. The conversion uses your batteries wattage to do that work. Which means your available watts drop. The loss is about 20%.
My advice is to buy devices that contain their own batteries. Simply plug it into your solar system and unplug it when charged.